Sökning: "Sigbritt Karlsson"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Sigbritt Karlsson.

  1. 1. Prevention of Biofilm Formation on Silicone Rubber Materials for Outdoor High Voltage Insulators

    Författare :Sevil Atari Jabarzadeh; Sigbritt Karlsson; Ferruccio Doghieri; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High voltage insulator; silicone rubber; biofouling; biofilm; biocide; superhydrophobicity; self-cleaning; hierarchical roughness;

    Sammanfattning : Microbial colonization on the surface of silicone rubber high voltage outdoor insulators often results in the formation of highly hydrated biofilm that influence the surface properties, such as surface hydrophobicity. The loss of hydrophobicity might lead to dry band formation, and, in the worst cases, flashover and failure of the insulator. LÄS MER

  2. 2. Preparation, characterisation and wetting of fluorinated cellulose surfaces

    Författare :Christian Aulin; Lars Wågberg; Sigbritt Karlsson; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : This thesis deals with the wetting by oil mixtures of two different model cellulose surfaces. The surfaces studied were a regenerated cellulose (RG) surface prepared by spin-coating, and a film consisting of polyelectrolyte multilayers (PEM) of Poly(ethyleneimine) (PEI) and a carboxymethylated Microfibrillated Cellulose (MFC). LÄS MER

  3. 3. The warship Vasa : A Study of Lignin, Extractives and Acids in the oak wood

    Författare :Dina Dedic; Monica Ek; Bjarne Holmbom; Sigbritt Karlsson; KTH; []
    Nyckelord :;

    Sammanfattning : The oak wood timbers of the 17th century Swedish warship Vasa are weak. The weakening has been attributed to cellulose degradation, which is more extensive in the interior of the timbers compared to the surface regions. Further, the mechanism of cellulose degradation was attributed to oxidative reactions involving iron as a catalyst. LÄS MER

  4. 4. New Mass Spectrometric Methods for Structure Analysis of Carboxymethyl Cellulose

    Författare :Jonas Enebro; Sigbritt Karlsson; Dane Momcilovic; Ulf Germgård; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; carboxymethyl cellulose; substituent distribution; rheology; enzyme hydrolysis; cellulase; permethylation; liquid chromatography; MALDI; ESI; mass spectrometry; Polymer chemistry; Polymerkemi;

    Sammanfattning : Carboxymethyl cellulose (CMC) is a cellulose derivative, made from cellulose by introduction of carboxymethyl groups along the molecules. The properties of CMC are affected by several parameters where the molar mass and molar mass distribution, degree of substitution (DS) and the distribution pattern along, and between, the cellulose molecules are the most prominent. LÄS MER

  5. 5. Strategies for improving mechanical properties of polypropylene/cellulose composites

    Författare :Ana Espert; Sigbritt Karlsson; Carlos Gonzalez Sanchez; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Chemistry; polymer technology; chemical engineering; materials science; polymer; Kemi; Chemistry; Kemi;

    Sammanfattning : The interest for polypropylene/cellulose composites has experienced a great increase in different applications such as car interiors and construction materials. Cellulose fibres are inexpensive, renewable, biodegradable, they present lower density and their mechanical properties can be compared to those of inorganic fillers. LÄS MER